Worm-latch means for a slidable side-jaw wrench



p 1957 F. G. COUGHLIN WORM-LATCH MEANS FOR A SLIDABLE SIDE-JAW WRENCHFiled Nov. 9, 1955 IN VEN TOR, franc/Ls 6. 0055/1 i172 Arfo rwgy.

. w 1 3 It United States Patent WORM-LATCH MEANS FOR A SLIDABLE SIDE-JAWWRENCH Francis G. Coughlin, Philadelphia, Pa. Application November 9,1955, Serial No. 545,834

3 Claims. (Cl. 81-165) The object of the invention is to provideimprovements in wrenches, and more particularly in means to positivelyresist accidental shifting of the usual jaw-adjusting means, andconsequently to maintain a predetermined adjustment when once setagainst the tendency to lose such adjustment, as a result of the usuallooseness that characterizes such tools, and the ever-presentpossibility of consequent alteration from a preset distance between thejaws.

Another object is to provide a wrench that essentially comprises tworelatively adjustable jaw elements, and any well known form of worm gearcarried by one of said elements in normal mesh with a rack carried bythe other element for adjusting the space between the jaws of saidelements, said worm gear being characterized by an axial extension thatis provided with a roughened surface, and which extension projectslaterally beyond the outer surface of the adjacent portions of thewrench, in combination with a lever that is pivotally connected withsaid wrench at a mid-point, and comprises in one direction afinger-engageable portion, while its opposite end is provided with aroughened surface adapted to normally engage and interlock with thecorresponding surface of said gear extension, and a spring to yieldinglymaintain such engagement until pressure upon said finger-engageableportion forces said roughened surfaces apart, and which thereby and thenonly permits said worm gear to be revolved and the distance between saidjaw elements increased or decreased.

A further object is to provide a wrench of the general construction asbroadly described in the foregoing paragraph, but in which the axialextension of the worm gear axis preferably is generally convexly shaped,as for example in the shape of a bevel gear, and the adjacent surface ofthe locking lever is provided with a generally concavely shaped surface,said last mentioned surface being provided with complementarilyroughened irregularities, such for example as the irregularities of aninternal bevel gear, whereby in the absence of manual pressure appliedto said lever said surfaces are maintained in interlocking engagement,said worm gear is positively held against rotation, and the distancebetween the jaws of the wrench is positively maintained.

With the objects thus briefly set forth, the invention comprises furtherdetails of construction and operation, which are fully described in thefollowing specification, when read in conjunction with the accompanyingdrawings, in which Fig. 1 is a .plan view of a wrench comprising oneembodiment of the invention; Fig. 2 is an enlarged fragmentary view ofthe head of the same; and Fig. 3 is a section on the line 33 of Fig. 2.

Referring to the drawings, an adjustable bolt and nut type of wrench isshown as comprising the usual elongated handle 1, of which one end isprovided with an angularly enlarged head 2, having a freely projecting,right-angle extension 3 at one end, provided'with a clamping surface 4and an inwardly positioned surface 5, which serves 2,804,793 PatentedSept. 3, 1957 as an inner limit for movement of a bolt or nut againstwhich said jaw surface is placed. Extending diagonally through said headand parallel with said inner surface 5 is a bore 6, in which isreciprocatively positioned the base portion 7 of a freely projectingmovable jaw 8 having a clamping surface 9, between which and saidfirstmentioned surface 4 a bolt or nut may be clamped.

The enlarged head 2 is provided with a windowlike aperture 10 into whichsaid bore opens through two of its opposite and one interveningsurfaces. Within said aperture is rotatably positioned a worm 11, thatis provided upon its innermost end with an axially directed trunnion 12,revolvably positioned in a bore 13 in one side wall of said aperture,while in the opposite direction said worm is provided with an axiallyprojecting trunnion 14, that extends through a bore 15 in that end wallof said aperture adjacent to the movable jaw 8. Rotation of said worm bymanual engagement with its characteristic spiral ridge operates to varythe distance between said jaw surfaces in the usual manner.

The outermost end of the worm trunnion 14 is provided with a radiallyenlarged terminal 16 having a suitably serrated or otherwise roughenedconvex outer surface, the irregularities of which may take the form ofradially extending, circumferentially spaced ridges and grooves, such asare suggested by a bevel-gear. Complementary to this surface is theconcave surface 17 of the transversely enlarged head 18 of one end of alever, which medially comprises a pair of transversely spaced angularlydirected cars 19, that are positioned upon the opposite sides of saidhandle shank adjacent to the windowlike aperture 10, and beyond whilesaid lever comprises a finger engageable end portion 20. Said endportion is normally maintained spaced from said handle under theinfluence of a coil spring 21 whose opposite end extends into and issecured within a bore 22 in said handle.

Having thus described my invention, what I claim and desire to protectby Letters Patent of the United States is:

l, A wrench, comprising a fixed element having a work surface, aclamping element having a work surface substantially parallel with saidfirst work surface and a shank movable longitudinally in a pathangularly disposed with respect to said work surface, said shank beingprovided with rack teeth, a worm longitudinally fixed but rotatablycarried by said fixed element and engaging said rack teeth, one end ofsaid worm being provided with bevel gear teeth, and a member movablycarried by said fixed element and having a surface provided withconcavely recessed bevel gear teeth normally in locking engagement withthe teeth of said worm end, to positively prevent accidental rotation ofsaid worm and variation in the distance between said work surfaces asthe interengageable teeth wear.

2. A wrench, comprising a fixed element having a manually engageableportion and a work surface, a clamping element having a work surfacesubstantially parallel with said first work surface and a shank movablelongitudinally in a path angularly disposed with respect to said worksurface, said shank being provided with rack teeth, a wormlongitudinally fixed but rotatably carried by said fixed element andengaging said rack teeth, one end of said worm being provided with aconvex surface having bevel gear teeth, and a lever pivotal-1y carriedby said fixed element and having a concave surface provided with bevelgear teeth that are complementary to and normally in locking engagementwith said first gear teeth, to positively prevent accidental rotation ofsaid worm and variation in the distance between said work surfaces assaid gear teeth Wear, and resilient means to normally maintain saidlever in operative position.

3. A wrench, comprising a fixed element pierced by a windowlike apertureand having a work surface, said element being also provided with atransversely extending channel opening in opposite directions into saidaperture, a clamping element having a base portion reciprocatable insaid channel and a work surface substantially parallel with said firstWork surface, said base portion being provided with rack teeth, a Wormlongitudinally fixed within said aperture and having a spiral rib inengagement with said rack teeth, said Worm in one direction having anaxial extension that projects laterally from one side of said fixedelement and is provided with a surface having regularly arranged bevelgear teeth, a lever pivotally carried by said fixed element and atoneend having a surface provided with concavely recessed bevel gear teethnormally engageable with said first gear teeth, to

4 positively prevent accidental rotation of said worm and variation inthe distance between said Work surfaces, and resilient means to normallymaintain said lever in operative position, the opposite end of saidlever being manually actuatable to shift said lever against saidresilient means to separate said toothed surfaces.

References Cited in the file of this patent UNITED STATES PATENTS RylandOct. 2,

